1 /* auditfilter.c -- filtering of audit events
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/security.h>
38 * Synchronizes writes and blocking reads of audit's filterlist
39 * data. Rcu is used to traverse the filterlist and access
40 * contents of structs audit_entry, audit_watch and opaque
41 * LSM rules during filtering. If modified, these structures
42 * must be copied and replace their counterparts in the filterlist.
43 * An audit_parent struct is not accessed during filtering, so may
44 * be written directly provided audit_filter_mutex is held.
47 /* Audit filter lists, defined in <linux/audit.h> */
48 struct list_head audit_filter_list
[AUDIT_NR_FILTERS
] = {
49 LIST_HEAD_INIT(audit_filter_list
[0]),
50 LIST_HEAD_INIT(audit_filter_list
[1]),
51 LIST_HEAD_INIT(audit_filter_list
[2]),
52 LIST_HEAD_INIT(audit_filter_list
[3]),
53 LIST_HEAD_INIT(audit_filter_list
[4]),
54 LIST_HEAD_INIT(audit_filter_list
[5]),
55 #if AUDIT_NR_FILTERS != 6
56 #error Fix audit_filter_list initialiser
59 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
60 LIST_HEAD_INIT(audit_rules_list
[0]),
61 LIST_HEAD_INIT(audit_rules_list
[1]),
62 LIST_HEAD_INIT(audit_rules_list
[2]),
63 LIST_HEAD_INIT(audit_rules_list
[3]),
64 LIST_HEAD_INIT(audit_rules_list
[4]),
65 LIST_HEAD_INIT(audit_rules_list
[5]),
68 DEFINE_MUTEX(audit_filter_mutex
);
70 static inline void audit_free_rule(struct audit_entry
*e
)
73 struct audit_krule
*erule
= &e
->rule
;
75 /* some rules don't have associated watches */
77 audit_put_watch(erule
->watch
);
79 for (i
= 0; i
< erule
->field_count
; i
++) {
80 struct audit_field
*f
= &erule
->fields
[i
];
82 security_audit_rule_free(f
->lsm_rule
);
85 kfree(erule
->filterkey
);
89 void audit_free_rule_rcu(struct rcu_head
*head
)
91 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
95 /* Initialize an audit filterlist entry. */
96 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
98 struct audit_entry
*entry
;
99 struct audit_field
*fields
;
101 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
102 if (unlikely(!entry
))
105 fields
= kzalloc(sizeof(*fields
) * field_count
, GFP_KERNEL
);
106 if (unlikely(!fields
)) {
110 entry
->rule
.fields
= fields
;
115 /* Unpack a filter field's string representation from user-space
117 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
121 if (!*bufp
|| (len
== 0) || (len
> *remain
))
122 return ERR_PTR(-EINVAL
);
124 /* Of the currently implemented string fields, PATH_MAX
125 * defines the longest valid length.
128 return ERR_PTR(-ENAMETOOLONG
);
130 str
= kmalloc(len
+ 1, GFP_KERNEL
);
132 return ERR_PTR(-ENOMEM
);
134 memcpy(str
, *bufp
, len
);
142 /* Translate an inode field to kernel respresentation. */
143 static inline int audit_to_inode(struct audit_krule
*krule
,
144 struct audit_field
*f
)
146 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
147 krule
->watch
|| krule
->inode_f
|| krule
->tree
||
148 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
155 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
157 int __init
audit_register_class(int class, unsigned *list
)
159 __u32
*p
= kzalloc(AUDIT_BITMASK_SIZE
* sizeof(__u32
), GFP_KERNEL
);
162 while (*list
!= ~0U) {
163 unsigned n
= *list
++;
164 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
168 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
170 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
178 int audit_match_class(int class, unsigned syscall
)
180 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
182 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
184 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
187 #ifdef CONFIG_AUDITSYSCALL
188 static inline int audit_match_class_bits(int class, u32
*mask
)
192 if (classes
[class]) {
193 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
194 if (mask
[i
] & classes
[class][i
])
200 static int audit_match_signal(struct audit_entry
*entry
)
202 struct audit_field
*arch
= entry
->rule
.arch_f
;
205 /* When arch is unspecified, we must check both masks on biarch
206 * as syscall number alone is ambiguous. */
207 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
209 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
213 switch(audit_classify_arch(arch
->val
)) {
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
217 case 1: /* 32bit on biarch */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
226 /* Common user-space to kernel rule translation. */
227 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule
*rule
)
230 struct audit_entry
*entry
;
234 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
238 #ifdef CONFIG_AUDITSYSCALL
239 case AUDIT_FILTER_ENTRY
:
240 if (rule
->action
== AUDIT_ALWAYS
)
242 case AUDIT_FILTER_EXIT
:
243 case AUDIT_FILTER_TASK
:
245 case AUDIT_FILTER_USER
:
246 case AUDIT_FILTER_TYPE
:
249 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
250 printk(KERN_ERR
"AUDIT_POSSIBLE is deprecated\n");
253 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
255 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
259 entry
= audit_init_entry(rule
->field_count
);
263 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
264 entry
->rule
.listnr
= listnr
;
265 entry
->rule
.action
= rule
->action
;
266 entry
->rule
.field_count
= rule
->field_count
;
268 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
269 entry
->rule
.mask
[i
] = rule
->mask
[i
];
271 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
272 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
273 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
276 if (!(*p
& AUDIT_BIT(bit
)))
278 *p
&= ~AUDIT_BIT(bit
);
282 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
283 entry
->rule
.mask
[j
] |= class[j
];
293 static u32 audit_ops
[] =
295 [Audit_equal
] = AUDIT_EQUAL
,
296 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
297 [Audit_bitmask
] = AUDIT_BIT_MASK
,
298 [Audit_bittest
] = AUDIT_BIT_TEST
,
299 [Audit_lt
] = AUDIT_LESS_THAN
,
300 [Audit_gt
] = AUDIT_GREATER_THAN
,
301 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
302 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
305 static u32
audit_to_op(u32 op
)
308 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
314 /* Translate struct audit_rule to kernel's rule respresentation.
315 * Exists for backward compatibility with userspace. */
316 static struct audit_entry
*audit_rule_to_entry(struct audit_rule
*rule
)
318 struct audit_entry
*entry
;
322 entry
= audit_to_entry_common(rule
);
326 for (i
= 0; i
< rule
->field_count
; i
++) {
327 struct audit_field
*f
= &entry
->rule
.fields
[i
];
330 n
= rule
->fields
[i
] & (AUDIT_NEGATE
|AUDIT_OPERATORS
);
332 /* Support for legacy operators where
333 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
334 if (n
& AUDIT_NEGATE
)
335 f
->op
= Audit_not_equal
;
339 f
->op
= audit_to_op(n
);
341 entry
->rule
.vers_ops
= (n
& AUDIT_OPERATORS
) ? 2 : 1;
343 f
->type
= rule
->fields
[i
] & ~(AUDIT_NEGATE
|AUDIT_OPERATORS
);
344 f
->val
= rule
->values
[i
];
345 f
->uid
= INVALID_UID
;
346 f
->gid
= INVALID_GID
;
349 if (f
->op
== Audit_bad
)
360 /* bit ops not implemented for uid comparisons */
361 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
364 f
->uid
= make_kuid(current_user_ns(), f
->val
);
365 if (!uid_valid(f
->uid
))
372 /* bit ops not implemented for gid comparisons */
373 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
376 f
->gid
= make_kgid(current_user_ns(), f
->val
);
377 if (!gid_valid(f
->gid
))
388 /* bit ops are only useful on syscall args */
389 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
397 /* arch is only allowed to be = or != */
399 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
401 entry
->rule
.arch_f
= f
;
408 if (f
->val
& ~S_IFMT
)
412 err
= audit_to_inode(&entry
->rule
, f
);
419 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
420 entry
->rule
.inode_f
= NULL
;
426 audit_free_rule(entry
);
430 /* Translate struct audit_rule_data to kernel's rule respresentation. */
431 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
435 struct audit_entry
*entry
;
437 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
441 entry
= audit_to_entry_common((struct audit_rule
*)data
);
446 entry
->rule
.vers_ops
= 2;
447 for (i
= 0; i
< data
->field_count
; i
++) {
448 struct audit_field
*f
= &entry
->rule
.fields
[i
];
452 f
->op
= audit_to_op(data
->fieldflags
[i
]);
453 if (f
->op
== Audit_bad
)
456 f
->type
= data
->fields
[i
];
457 f
->val
= data
->values
[i
];
458 f
->uid
= INVALID_UID
;
459 f
->gid
= INVALID_GID
;
469 /* bit ops not implemented for uid comparisons */
470 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
473 f
->uid
= make_kuid(current_user_ns(), f
->val
);
474 if (!uid_valid(f
->uid
))
482 /* bit ops not implemented for gid comparisons */
483 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
486 f
->gid
= make_kgid(current_user_ns(), f
->val
);
487 if (!gid_valid(f
->gid
))
504 entry
->rule
.arch_f
= f
;
506 case AUDIT_SUBJ_USER
:
507 case AUDIT_SUBJ_ROLE
:
508 case AUDIT_SUBJ_TYPE
:
514 case AUDIT_OBJ_LEV_LOW
:
515 case AUDIT_OBJ_LEV_HIGH
:
516 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
519 entry
->rule
.buflen
+= f
->val
;
521 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
522 (void **)&f
->lsm_rule
);
523 /* Keep currently invalid fields around in case they
524 * become valid after a policy reload. */
525 if (err
== -EINVAL
) {
526 printk(KERN_WARNING
"audit rule for LSM "
527 "\'%s\' is invalid\n", str
);
537 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
540 entry
->rule
.buflen
+= f
->val
;
542 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
549 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
552 entry
->rule
.buflen
+= f
->val
;
554 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
560 err
= audit_to_inode(&entry
->rule
, f
);
564 case AUDIT_FILTERKEY
:
565 if (entry
->rule
.filterkey
|| f
->val
> AUDIT_MAX_KEY_LEN
)
567 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
570 entry
->rule
.buflen
+= f
->val
;
571 entry
->rule
.filterkey
= str
;
578 if (f
->val
& ~S_IFMT
)
581 case AUDIT_FIELD_COMPARE
:
582 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
590 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
591 entry
->rule
.inode_f
= NULL
;
597 if (entry
->rule
.watch
)
598 audit_put_watch(entry
->rule
.watch
); /* matches initial get */
599 if (entry
->rule
.tree
)
600 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
601 audit_free_rule(entry
);
605 /* Pack a filter field's string representation into data block. */
606 static inline size_t audit_pack_string(void **bufp
, const char *str
)
608 size_t len
= strlen(str
);
610 memcpy(*bufp
, str
, len
);
616 /* Translate kernel rule respresentation to struct audit_rule.
617 * Exists for backward compatibility with userspace. */
618 static struct audit_rule
*audit_krule_to_rule(struct audit_krule
*krule
)
620 struct audit_rule
*rule
;
623 rule
= kzalloc(sizeof(*rule
), GFP_KERNEL
);
627 rule
->flags
= krule
->flags
| krule
->listnr
;
628 rule
->action
= krule
->action
;
629 rule
->field_count
= krule
->field_count
;
630 for (i
= 0; i
< rule
->field_count
; i
++) {
631 rule
->values
[i
] = krule
->fields
[i
].val
;
632 rule
->fields
[i
] = krule
->fields
[i
].type
;
634 if (krule
->vers_ops
== 1) {
635 if (krule
->fields
[i
].op
== Audit_not_equal
)
636 rule
->fields
[i
] |= AUDIT_NEGATE
;
638 rule
->fields
[i
] |= audit_ops
[krule
->fields
[i
].op
];
641 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) rule
->mask
[i
] = krule
->mask
[i
];
646 /* Translate kernel rule respresentation to struct audit_rule_data. */
647 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
649 struct audit_rule_data
*data
;
653 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
656 memset(data
, 0, sizeof(*data
));
658 data
->flags
= krule
->flags
| krule
->listnr
;
659 data
->action
= krule
->action
;
660 data
->field_count
= krule
->field_count
;
662 for (i
= 0; i
< data
->field_count
; i
++) {
663 struct audit_field
*f
= &krule
->fields
[i
];
665 data
->fields
[i
] = f
->type
;
666 data
->fieldflags
[i
] = audit_ops
[f
->op
];
668 case AUDIT_SUBJ_USER
:
669 case AUDIT_SUBJ_ROLE
:
670 case AUDIT_SUBJ_TYPE
:
676 case AUDIT_OBJ_LEV_LOW
:
677 case AUDIT_OBJ_LEV_HIGH
:
678 data
->buflen
+= data
->values
[i
] =
679 audit_pack_string(&bufp
, f
->lsm_str
);
682 data
->buflen
+= data
->values
[i
] =
683 audit_pack_string(&bufp
,
684 audit_watch_path(krule
->watch
));
687 data
->buflen
+= data
->values
[i
] =
688 audit_pack_string(&bufp
,
689 audit_tree_path(krule
->tree
));
691 case AUDIT_FILTERKEY
:
692 data
->buflen
+= data
->values
[i
] =
693 audit_pack_string(&bufp
, krule
->filterkey
);
696 data
->values
[i
] = f
->val
;
699 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
704 /* Compare two rules in kernel format. Considered success if rules
706 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
710 if (a
->flags
!= b
->flags
||
711 a
->listnr
!= b
->listnr
||
712 a
->action
!= b
->action
||
713 a
->field_count
!= b
->field_count
)
716 for (i
= 0; i
< a
->field_count
; i
++) {
717 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
718 a
->fields
[i
].op
!= b
->fields
[i
].op
)
721 switch(a
->fields
[i
].type
) {
722 case AUDIT_SUBJ_USER
:
723 case AUDIT_SUBJ_ROLE
:
724 case AUDIT_SUBJ_TYPE
:
730 case AUDIT_OBJ_LEV_LOW
:
731 case AUDIT_OBJ_LEV_HIGH
:
732 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
736 if (strcmp(audit_watch_path(a
->watch
),
737 audit_watch_path(b
->watch
)))
741 if (strcmp(audit_tree_path(a
->tree
),
742 audit_tree_path(b
->tree
)))
745 case AUDIT_FILTERKEY
:
746 /* both filterkeys exist based on above type compare */
747 if (strcmp(a
->filterkey
, b
->filterkey
))
756 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
764 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
768 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
773 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
774 if (a
->mask
[i
] != b
->mask
[i
])
780 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
782 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
783 struct audit_field
*sf
)
788 /* our own copy of lsm_str */
789 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
790 if (unlikely(!lsm_str
))
792 df
->lsm_str
= lsm_str
;
794 /* our own (refreshed) copy of lsm_rule */
795 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
796 (void **)&df
->lsm_rule
);
797 /* Keep currently invalid fields around in case they
798 * become valid after a policy reload. */
799 if (ret
== -EINVAL
) {
800 printk(KERN_WARNING
"audit rule for LSM \'%s\' is "
801 "invalid\n", df
->lsm_str
);
808 /* Duplicate an audit rule. This will be a deep copy with the exception
809 * of the watch - that pointer is carried over. The LSM specific fields
810 * will be updated in the copy. The point is to be able to replace the old
811 * rule with the new rule in the filterlist, then free the old rule.
812 * The rlist element is undefined; list manipulations are handled apart from
813 * the initial copy. */
814 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
816 u32 fcount
= old
->field_count
;
817 struct audit_entry
*entry
;
818 struct audit_krule
*new;
822 entry
= audit_init_entry(fcount
);
823 if (unlikely(!entry
))
824 return ERR_PTR(-ENOMEM
);
827 new->vers_ops
= old
->vers_ops
;
828 new->flags
= old
->flags
;
829 new->listnr
= old
->listnr
;
830 new->action
= old
->action
;
831 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
832 new->mask
[i
] = old
->mask
[i
];
833 new->prio
= old
->prio
;
834 new->buflen
= old
->buflen
;
835 new->inode_f
= old
->inode_f
;
836 new->field_count
= old
->field_count
;
839 * note that we are OK with not refcounting here; audit_match_tree()
840 * never dereferences tree and we can't get false positives there
841 * since we'd have to have rule gone from the list *and* removed
842 * before the chunks found by lookup had been allocated, i.e. before
843 * the beginning of list scan.
845 new->tree
= old
->tree
;
846 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
848 /* deep copy this information, updating the lsm_rule fields, because
849 * the originals will all be freed when the old rule is freed. */
850 for (i
= 0; i
< fcount
; i
++) {
851 switch (new->fields
[i
].type
) {
852 case AUDIT_SUBJ_USER
:
853 case AUDIT_SUBJ_ROLE
:
854 case AUDIT_SUBJ_TYPE
:
860 case AUDIT_OBJ_LEV_LOW
:
861 case AUDIT_OBJ_LEV_HIGH
:
862 err
= audit_dupe_lsm_field(&new->fields
[i
],
865 case AUDIT_FILTERKEY
:
866 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
873 audit_free_rule(entry
);
879 audit_get_watch(old
->watch
);
880 new->watch
= old
->watch
;
886 /* Find an existing audit rule.
887 * Caller must hold audit_filter_mutex to prevent stale rule data. */
888 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
889 struct list_head
**p
)
891 struct audit_entry
*e
, *found
= NULL
;
892 struct list_head
*list
;
895 if (entry
->rule
.inode_f
) {
896 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
897 *p
= list
= &audit_inode_hash
[h
];
898 } else if (entry
->rule
.watch
) {
899 /* we don't know the inode number, so must walk entire hash */
900 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
901 list
= &audit_inode_hash
[h
];
902 list_for_each_entry(e
, list
, list
)
903 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
910 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
913 list_for_each_entry(e
, list
, list
)
914 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
923 static u64 prio_low
= ~0ULL/2;
924 static u64 prio_high
= ~0ULL/2 - 1;
926 /* Add rule to given filterlist if not a duplicate. */
927 static inline int audit_add_rule(struct audit_entry
*entry
)
929 struct audit_entry
*e
;
930 struct audit_watch
*watch
= entry
->rule
.watch
;
931 struct audit_tree
*tree
= entry
->rule
.tree
;
932 struct list_head
*list
;
934 #ifdef CONFIG_AUDITSYSCALL
937 /* If either of these, don't count towards total */
938 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
939 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
943 mutex_lock(&audit_filter_mutex
);
944 e
= audit_find_rule(entry
, &list
);
946 mutex_unlock(&audit_filter_mutex
);
948 /* normally audit_add_tree_rule() will free it on failure */
950 audit_put_tree(tree
);
955 /* audit_filter_mutex is dropped and re-taken during this call */
956 err
= audit_add_watch(&entry
->rule
, &list
);
958 mutex_unlock(&audit_filter_mutex
);
963 err
= audit_add_tree_rule(&entry
->rule
);
965 mutex_unlock(&audit_filter_mutex
);
970 entry
->rule
.prio
= ~0ULL;
971 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
) {
972 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
973 entry
->rule
.prio
= ++prio_high
;
975 entry
->rule
.prio
= --prio_low
;
978 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
979 list_add(&entry
->rule
.list
,
980 &audit_rules_list
[entry
->rule
.listnr
]);
981 list_add_rcu(&entry
->list
, list
);
982 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
984 list_add_tail(&entry
->rule
.list
,
985 &audit_rules_list
[entry
->rule
.listnr
]);
986 list_add_tail_rcu(&entry
->list
, list
);
988 #ifdef CONFIG_AUDITSYSCALL
992 if (!audit_match_signal(entry
))
995 mutex_unlock(&audit_filter_mutex
);
1001 audit_put_watch(watch
); /* tmp watch, matches initial get */
1005 /* Remove an existing rule from filterlist. */
1006 static inline int audit_del_rule(struct audit_entry
*entry
)
1008 struct audit_entry
*e
;
1009 struct audit_watch
*watch
= entry
->rule
.watch
;
1010 struct audit_tree
*tree
= entry
->rule
.tree
;
1011 struct list_head
*list
;
1013 #ifdef CONFIG_AUDITSYSCALL
1016 /* If either of these, don't count towards total */
1017 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
1018 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
1022 mutex_lock(&audit_filter_mutex
);
1023 e
= audit_find_rule(entry
, &list
);
1025 mutex_unlock(&audit_filter_mutex
);
1031 audit_remove_watch_rule(&e
->rule
);
1034 audit_remove_tree_rule(&e
->rule
);
1036 list_del_rcu(&e
->list
);
1037 list_del(&e
->rule
.list
);
1038 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1040 #ifdef CONFIG_AUDITSYSCALL
1044 if (!audit_match_signal(entry
))
1047 mutex_unlock(&audit_filter_mutex
);
1051 audit_put_watch(watch
); /* match initial get */
1053 audit_put_tree(tree
); /* that's the temporary one */
1058 /* List rules using struct audit_rule. Exists for backward
1059 * compatibility with userspace. */
1060 static void audit_list(int pid
, int seq
, struct sk_buff_head
*q
)
1062 struct sk_buff
*skb
;
1063 struct audit_krule
*r
;
1066 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1067 * iterator to sync with list writers. */
1068 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1069 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1070 struct audit_rule
*rule
;
1072 rule
= audit_krule_to_rule(r
);
1073 if (unlikely(!rule
))
1075 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1076 rule
, sizeof(*rule
));
1078 skb_queue_tail(q
, skb
);
1082 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 1, 1, NULL
, 0);
1084 skb_queue_tail(q
, skb
);
1087 /* List rules using struct audit_rule_data. */
1088 static void audit_list_rules(int pid
, int seq
, struct sk_buff_head
*q
)
1090 struct sk_buff
*skb
;
1091 struct audit_krule
*r
;
1094 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1095 * iterator to sync with list writers. */
1096 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1097 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1098 struct audit_rule_data
*data
;
1100 data
= audit_krule_to_data(r
);
1101 if (unlikely(!data
))
1103 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1104 data
, sizeof(*data
) + data
->buflen
);
1106 skb_queue_tail(q
, skb
);
1110 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1112 skb_queue_tail(q
, skb
);
1115 /* Log rule additions and removals */
1116 static void audit_log_rule_change(kuid_t loginuid
, u32 sessionid
, u32 sid
,
1117 char *action
, struct audit_krule
*rule
,
1120 struct audit_buffer
*ab
;
1125 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1128 audit_log_format(ab
, "auid=%u ses=%u",
1129 from_kuid(&init_user_ns
, loginuid
), sessionid
);
1133 if (security_secid_to_secctx(sid
, &ctx
, &len
))
1134 audit_log_format(ab
, " ssid=%u", sid
);
1136 audit_log_format(ab
, " subj=%s", ctx
);
1137 security_release_secctx(ctx
, len
);
1140 audit_log_format(ab
, " op=");
1141 audit_log_string(ab
, action
);
1142 audit_log_key(ab
, rule
->filterkey
);
1143 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1148 * audit_receive_filter - apply all rules to the specified message type
1149 * @type: audit message type
1150 * @pid: target pid for netlink audit messages
1151 * @seq: netlink audit message sequence (serial) number
1152 * @data: payload data
1153 * @datasz: size of payload data
1154 * @loginuid: loginuid of sender
1155 * @sessionid: sessionid for netlink audit message
1156 * @sid: SE Linux Security ID of sender
1158 int audit_receive_filter(int type
, int pid
, int seq
, void *data
,
1159 size_t datasz
, kuid_t loginuid
, u32 sessionid
, u32 sid
)
1161 struct task_struct
*tsk
;
1162 struct audit_netlink_list
*dest
;
1164 struct audit_entry
*entry
;
1168 case AUDIT_LIST_RULES
:
1169 /* We can't just spew out the rules here because we might fill
1170 * the available socket buffer space and deadlock waiting for
1171 * auditctl to read from it... which isn't ever going to
1172 * happen if we're actually running in the context of auditctl
1173 * trying to _send_ the stuff */
1175 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1179 skb_queue_head_init(&dest
->q
);
1181 mutex_lock(&audit_filter_mutex
);
1182 if (type
== AUDIT_LIST
)
1183 audit_list(pid
, seq
, &dest
->q
);
1185 audit_list_rules(pid
, seq
, &dest
->q
);
1186 mutex_unlock(&audit_filter_mutex
);
1188 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1190 skb_queue_purge(&dest
->q
);
1196 case AUDIT_ADD_RULE
:
1197 if (type
== AUDIT_ADD
)
1198 entry
= audit_rule_to_entry(data
);
1200 entry
= audit_data_to_entry(data
, datasz
);
1202 return PTR_ERR(entry
);
1204 err
= audit_add_rule(entry
);
1205 audit_log_rule_change(loginuid
, sessionid
, sid
, "add rule",
1206 &entry
->rule
, !err
);
1209 audit_free_rule(entry
);
1212 case AUDIT_DEL_RULE
:
1213 if (type
== AUDIT_DEL
)
1214 entry
= audit_rule_to_entry(data
);
1216 entry
= audit_data_to_entry(data
, datasz
);
1218 return PTR_ERR(entry
);
1220 err
= audit_del_rule(entry
);
1221 audit_log_rule_change(loginuid
, sessionid
, sid
, "remove rule",
1222 &entry
->rule
, !err
);
1224 audit_free_rule(entry
);
1233 int audit_comparator(u32 left
, u32 op
, u32 right
)
1237 return (left
== right
);
1238 case Audit_not_equal
:
1239 return (left
!= right
);
1241 return (left
< right
);
1243 return (left
<= right
);
1245 return (left
> right
);
1247 return (left
>= right
);
1249 return (left
& right
);
1251 return ((left
& right
) == right
);
1258 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1262 return uid_eq(left
, right
);
1263 case Audit_not_equal
:
1264 return !uid_eq(left
, right
);
1266 return uid_lt(left
, right
);
1268 return uid_lte(left
, right
);
1270 return uid_gt(left
, right
);
1272 return uid_gte(left
, right
);
1281 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1285 return gid_eq(left
, right
);
1286 case Audit_not_equal
:
1287 return !gid_eq(left
, right
);
1289 return gid_lt(left
, right
);
1291 return gid_lte(left
, right
);
1293 return gid_gt(left
, right
);
1295 return gid_gte(left
, right
);
1305 * parent_len - find the length of the parent portion of a pathname
1306 * @path: pathname of which to determine length
1308 int parent_len(const char *path
)
1313 plen
= strlen(path
);
1318 /* disregard trailing slashes */
1319 p
= path
+ plen
- 1;
1320 while ((*p
== '/') && (p
> path
))
1323 /* walk backward until we find the next slash or hit beginning */
1324 while ((*p
!= '/') && (p
> path
))
1327 /* did we find a slash? Then increment to include it in path */
1335 * audit_compare_dname_path - compare given dentry name with last component in
1336 * given path. Return of 0 indicates a match.
1337 * @dname: dentry name that we're comparing
1338 * @path: full pathname that we're comparing
1339 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1340 * here indicates that we must compute this value.
1342 int audit_compare_dname_path(const char *dname
, const char *path
, int parentlen
)
1347 dlen
= strlen(dname
);
1348 pathlen
= strlen(path
);
1352 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1353 if (pathlen
- parentlen
!= dlen
)
1356 p
= path
+ parentlen
;
1358 return strncmp(p
, dname
, dlen
);
1361 static int audit_filter_user_rules(struct audit_krule
*rule
,
1362 enum audit_state
*state
)
1366 for (i
= 0; i
< rule
->field_count
; i
++) {
1367 struct audit_field
*f
= &rule
->fields
[i
];
1373 result
= audit_comparator(task_pid_vnr(current
), f
->op
, f
->val
);
1376 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1379 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1381 case AUDIT_LOGINUID
:
1382 result
= audit_uid_comparator(audit_get_loginuid(current
),
1385 case AUDIT_SUBJ_USER
:
1386 case AUDIT_SUBJ_ROLE
:
1387 case AUDIT_SUBJ_TYPE
:
1388 case AUDIT_SUBJ_SEN
:
1389 case AUDIT_SUBJ_CLR
:
1391 security_task_getsecid(current
, &sid
);
1392 result
= security_audit_rule_match(sid
,
1404 switch (rule
->action
) {
1405 case AUDIT_NEVER
: *state
= AUDIT_DISABLED
; break;
1406 case AUDIT_ALWAYS
: *state
= AUDIT_RECORD_CONTEXT
; break;
1411 int audit_filter_user(void)
1413 enum audit_state state
= AUDIT_DISABLED
;
1414 struct audit_entry
*e
;
1418 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_USER
], list
) {
1419 if (audit_filter_user_rules(&e
->rule
, &state
)) {
1420 if (state
== AUDIT_DISABLED
)
1427 return ret
; /* Audit by default */
1430 int audit_filter_type(int type
)
1432 struct audit_entry
*e
;
1436 if (list_empty(&audit_filter_list
[AUDIT_FILTER_TYPE
]))
1437 goto unlock_and_return
;
1439 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_TYPE
],
1442 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1443 struct audit_field
*f
= &e
->rule
.fields
[i
];
1444 if (f
->type
== AUDIT_MSGTYPE
) {
1445 result
= audit_comparator(type
, f
->op
, f
->val
);
1451 goto unlock_and_return
;
1458 static int update_lsm_rule(struct audit_krule
*r
)
1460 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1461 struct audit_entry
*nentry
;
1464 if (!security_audit_rule_known(r
))
1467 nentry
= audit_dupe_rule(r
);
1468 if (IS_ERR(nentry
)) {
1469 /* save the first error encountered for the
1471 err
= PTR_ERR(nentry
);
1472 audit_panic("error updating LSM filters");
1474 list_del(&r
->rlist
);
1475 list_del_rcu(&entry
->list
);
1478 if (r
->watch
|| r
->tree
)
1479 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1480 list_replace_rcu(&entry
->list
, &nentry
->list
);
1481 list_replace(&r
->list
, &nentry
->rule
.list
);
1483 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1488 /* This function will re-initialize the lsm_rule field of all applicable rules.
1489 * It will traverse the filter lists serarching for rules that contain LSM
1490 * specific filter fields. When such a rule is found, it is copied, the
1491 * LSM field is re-initialized, and the old rule is replaced with the
1493 int audit_update_lsm_rules(void)
1495 struct audit_krule
*r
, *n
;
1498 /* audit_filter_mutex synchronizes the writers */
1499 mutex_lock(&audit_filter_mutex
);
1501 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1502 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1503 int res
= update_lsm_rule(r
);
1508 mutex_unlock(&audit_filter_mutex
);